Terahertz laser produces a peak power of 940 mW at about 4 THz

THz_laser
A thumb (and finger as well) dwarf a terahertz-emitting quantum-cascade laser that puts out a peak power of almost a watt. (Image: Vienna University of Technology)


Vienna, Austria--A dual-facet pulsed quantum-cascade laser (QCL) that emits terahertz radiation with a center wavelength of 3.9 THz and a (very) broad bandwidth of 0.42 THz was created by researchers at the Vienna University of Technology (TU VIenna).1 The device puts out 470 mW peak power per facet, for a total of 940 mW. Pulse durations were about 200 ns, with a pulse repetition rate of 10 kHz, but gated to emit at 10 Hz.

Although the TU Vienna pulsed terahertz QCL puts out a peak power of almost a watt, keep in mind that its average optical power is much lower -- on the order of a couple of miiliwatts at 10 kHz and a couple of microwatts at 10 Hz. For comparison, a continuous-wave (CW) QCL recently developed by a Swiss group produces 3 mW of terahertz optical power.

To achieve its maximum peak power, the TU Vienna QCL must be operated at 5 K (liquid-helium temperature), but can be operated at a reduced output at temperatures up to 122 K. At the liquid-nitrogen temperature of 70 K, the device puts out a peak power of about 600 mW (300 mW per facet).

The researchers joined two gallium arsenide (GaAs) symmetrical laser structures (GaAs/Al0.15Ga0.85As heterostructures) together via direct wafer bonding; the joining results in a nonlinear growth of about fourfold in laser-light production. In fact, joining more than two structures in this way could lead to a further boost in output, say the researchers.

REFERENCE:

1. Martin Brandstetter et al., Applied Physics Letters 103, 171113 (2013); doi: 10.1063/1.4826943




Most Popular Articles

50 YEARS OF GAS LASERS


Durable survivors evolve new forms

Webcasts

Laser Measurements Critical to Successful Additive Manufacturing Processes

Maximizing the stability of the variables going into any manufacturing process is what ensures ts consistency and high quality. Specifically, when a laser is...

Ray Optics Simulations with COMSOL Multiphysics

The Ray Optics Module can be used to simulate electromagnetic wave propagation when the wavelength is much smaller than the smallest geometric entity in the ...

Multichannel Spectroscopy: Technology and Applications

This webcast, sponsored by Hamamatsu, highlights some of the photonic technology used in spectroscopy, and the resulting applications.

Handheld Spectrometers

Spectroscopy is a powerful and versatile tool that traditionally often required a large and bulky instrument. The combination of compact optics and modern pa...

Fracking, climate change, and lasers:  new tools to reduce fugitive methane emissions

This webcast, sponsored by Hamamatsu Corporation, covers recent developments and field deployments of compact quantum-cascade-laser (QCL)-based methane senso...

Opportunities in the Mid-IR

The technology for exploiting the mid-IR is developing rapidly:  it includes quantum-cascade lasers and other sources, spectroscopic instruments of many...
White Papers

All About Aspheric Lenses

The most notable benefit of aspheric lenses is their ability to correct for spherical aberration....

Wavelength stabilized multi-kW diode laser systems

Wavelength stabilization of high-power diode laser systems is an important means to increase the ...

Narrow-line fiber-coupled modules for DPAL pumping

A new series of fiber coupled diode laser modules optimized for DPAL pumping is presented, featur...
Technical Digests

FREEFORM OPTICS: Top-notch capabilities lead to expanded possibilities

The use of free-form aspherical surfaces in an optical system can give it abilities impossible to...

RAMAN SPECTROSCOPY: The technical advances just keep coming

In Raman spectroscopy, light from a laser interacts with a test sample, undergoing a wavelength s...

ADHESIVES, SEALANTS, AND COATINGS: Solutions for optical technologies

A vast array of optical systems of various types and degrees of complexity require the use of adh...

Click here to have your products listed in the Laser Focus World Buyers Guide.
Social Activity
  •  
  •  
  •  
  •  
  •  
Copyright © 2007-2014. PennWell Corporation, Tulsa, OK. All Rights Reserved.PRIVACY POLICY | TERMS AND CONDITIONS